A user is allowed to create an 9-digit password, but it must satisfy the following requirements: The first 2 spots must be different letters of the alphabet (case is not sensitive) The next 5 spots must be different numbers from the set {0-9} The last 2 spots must be different non-alphanumeric symbols from the set {#, @, $, %} How many passwords are possible?
Permutations and Combinations
If there are 5 dishes, they can be relished in any order at a time. In permutation, it should be in a particular order. In combination, the order does not matter. Take 3 letters a, b, and c. The possible ways of pairing any two letters are ab, bc, ac, ba, cb and ca. It is in a particular order. So, this can be called the permutation of a, b, and c. But if the order does not matter then ab is the same as ba. Similarly, bc is the same as cb and ac is the same as ca. Here the list has ab, bc, and ac alone. This can be called the combination of a, b, and c.
Counting Theory
The fundamental counting principle is a rule that is used to count the total number of possible outcomes in a given situation.
solve with permutations
A user is allowed to create an 9-digit password, but it must satisfy the following requirements:
The first 2 spots must be different letters of the alphabet (case is not sensitive)
The next 5 spots must be different numbers from the set {0-9}
The last 2 spots must be different non-alphanumeric symbols from the set {#, @, $, %}
How many passwords are possible?
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